The present invention relates to a volume hologram laminate and a label for preparation of the volume hologram laminate, particularly to a volume hologram laminate and a label for preparation of the volume hologram laminate suitable as a color filter in a mono-color or full-color hologram product or liquid crystalline optical element.
Hitherto, a volume hologram laminate generally has a constitution in which an adhesive layer, a volume hologram layer, an adhesive layer and a transparent protecting layer are laminated in the described order on a substrate. The laminate has been used in applications for protecting a label with a volume hologram layer, i.e. on a substrate such as an identification card, and also has been used as a color filter in a liquid crystalline optical element. There is, however, such a problem that color tones of image information reproduced actually from a hologram are not agreed with recorded color tones. Particularly, it is desirable that a reproduced wavelength being agreed with a recorded wavelength as such as possible for use as a color filter in a full-color hologram product or liquid crystalline optical element.
Further, it is desirable to control and optionally set a reproduced wavelength not only for the case wherein a reproduced wavelength being agreed with a recorded wavelength but also for the case wherein a desirable reproduced wavelength is deviated from a recorded wavelength.
Thus, an object of a first invention is to provide a volume hologram laminate and a label for preparation of a volume hologram laminate in which a desirable reproduced wavelength can be controlled and set optionally.
Further, in the conventional volume holograms, means for making color tones of reproduced image from hologram being agreed with that of a subject to be recorded is required. Particularly, it is desirable that a reproduced wavelength being agreed with a recorded wavelength as much as possible. Furthermore, there may be a case where it is necessary to set an optional color tone suitable for specific purposes or requirements.
Thus, an object of a second invention is to provide a volume hologram laminate and a label for preparation of the volume hologram laminate by which a desirable reproduced wavelength being obtained by controlling the shifted amount of the reproduced wavelength from a recorded wavelength.
Further, in the conventional volume hologram laminate, there is a problem that an illuminating origin to be used for hologram reproducing is limited if a reproduced band-width of diffracted light is narrow when a hologram recorded in a hologram layer is reproduced. As a counterplan for the problem, a reproduced band-width of diffracted light is made wide by arranging a tuning film etc. adjacent to a volume hologram layer. For this method, however, there is a problem that a film thickness of a volume hologram laminate becomes thick.
Thus, an object of a third invention is to provide a volume hologram laminate and a label for preparation of the volume hologram laminate by which a reproduced band of refracting light can be made wide and brilliant hologram can be obtained.
A first invention is directed to the following aspects.
A volume hologram laminate according to a first aspect is one having a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protecting film formed on a substrate in the described order, characterized in that a substance for shifting a recorded wavelength to the volume hologram layer is contained in the first and/or the second adhesive layer(s) and in that a reproduced wavelength of hologram recorded in the volume hologram layer is controlled with shifting the substance between the layers or without shifting.
A volume hologram laminate according to a second aspect is one having a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protecting film formed on a substrate in the described order, characterized in that a substance for shifting a recorded wavelength to the volume hologram layer is contained in either one of the first and the second adhesive layers, in that the substance is not contained in other adhesive layer, and in that a reproduced wavelength of hologram recording recorded in the volume hologram layer is controlled with shifting the substance between the layers.
A volume hologram laminate according to a third aspect is one having a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protecting film formed on a substrate in the described order, characterized in that a substance for shifting a recorded wavelength to the volume hologram layer is contained in the first and in that the second adhesive layers and the substance is not shifted from the layers to the volume hologram layer.
A volume hologram laminate according to a fourth aspect is one having a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protecting film formed on a substrate in the described order, characterized in that a film for shifting a recorded wavelength is put between the first adhesive layer and the volume hologram layer or between the second adhesive layer and the volume hologram layer, in that a substance for shifting a recorded wavelength to the volume hologram layer is contained in one of the adhesive layers without the film, and in that a reproduced wavelength of hologram recorded in the volume hologram layer is controlled with shifting the substance between the respective adhesive layer and the film as well as between the adhesive layer and the volume hologram layer or without shifting.
The above-mentioned adhesive layer is preferably a crosslinking type two component adhesive which is crosslinked at the time of use by addition of a crosslinking agent.
The above-mentioned volume hologram layer comprises preferably a photopolymerizable compound, and the layer is recorded holographically.
The above-mentioned substance for shifting a recorded wavelength comprises preferably at least one compound of a photopolymerizable compound constituting the volume hologram layer, a plasticizer and a surfactant, or a tackifier, and polyalkylene glycol.
A label for preparation of a volume hologram laminate according to a fifth aspect is one having a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protecting film laminated on a release liner sheet in the described order, characterized in that a substance for shifting a recorded wavelength to the volume hologram layer is contained in the first and/or the second adhesive layer(s) and in that a reproduced wavelength of hologram recorded in the volume hologram layer is controlled with shifting the substance between the layers or without shifting.
A label for preparation of a volume hologram laminate according to a sixth aspect is one having a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protecting film formed on a release liner sheet in the described order, characterized in that a substance for shifting a recorded wavelength to the volume hologram layer is contained in either one of the first and the second adhesive layers, in that the substance is not contained in other adhesive layer, and in that a reproduced wavelength of hologram recording recorded in the volume hologram layer is controlled with shifting the substance between the layers.
A label for preparation of a volume hologram laminate according to a seventh aspect is one having a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protecting film formed on a release liner sheet in the described order, characterized in that a substance for shifting a recorded wavelength to the volume hologram layer is contained in the first and the second adhesive layers and in that the substance is not shifted from the layers to the volume hologram layer.
A label for preparation of a volume hologram laminate according to an eighth aspect is one having a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protecting film formed on a release liner sheet in the described order, characterized in that a film for shifting a recorded wavelength is put between the first adhesive layer and the volume hologram layer or between the second adhesive layer and the volume hologram layer, in that a substance for shifting a recorded wavelength to the volume hologram layer is contained in one of the adhesive layers without the film, and in that a reproduced wavelength of hologram recorded in the volume hologram layer is controlled with shifting the substance between the respective adhesive layer and the film as well as between the adhesive layer and the volume hologram layer or without shifting.
A first volume hologram laminate according to the invention is one having a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protecting film formed on a substrate in the described order, characterized in that a substance with a refractive index lower than that of the volume hologram layer for shifting a recorded wavelength is contained in the first and/or the second adhesive layer(s) and in that a reproduced wavelength of hologram recorded in the volume hologram layer is shifted to a short wavelength side.
A refractive index of the above-mentioned substance for shifting a recorded wavelength is preferably at least 0.1 at 25xc2x0 C. lower than that of the volume hologram layer.
The above-mentioned substance for shifting a recorded wavelength is preferably at least one of silicone type compounds and fluorine type compounds.
A second volume hologram laminate according to the invention is one having a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protecting film formed on a substrate in the described order, characterized in that a substance with a refractive index higher than that of the volume hologram layer for shifting a recorded wavelength is contained in the first and/or the second adhesive layer(s) and in that a reproduced wavelength of hologram recorded in the volume hologram layer is shifted to a long wavelength side.
A refractive index of the substance for shifting a recorded wavelength in the second volume hologram laminate according to the invention is preferably at least 0.06 at 25xc2x0 C. higher than that of the volume hologram layer.
The substance for shifting a recorded wave length in the second volume hologram laminate according to the invention is preferably at least one of aromatic compounds, rosin type tackifiers, terpene type tackifiers and synthetic resin type tackifiers.
The above-mentioned adhesive layer is preferably formed of a crosslinking type two component adhesive which is crosslinked at the time of use by addition of a crosslinking agent.
The above-mentioned volume hologram layer comprises preferably a photopolymerizable compound, and the layer is recorded holographically.
A first label for preparation of a volume hologram laminate according to the invention is one having a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protecting film formed on a release liner sheet in the described order, characterized in that a substance with a refractive index lower than that of the volume hologram layer for shifting a recorded wavelength is contained in the first and/or the second adhesive layer(s) and in that a reproduced wavelength of hologram recorded in the volume hologram layer is shifted to a short wavelength side.
A second label for preparation of a volume hologram laminate according to the invention is one having a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protecting film laminated on a release liner sheet in the described order, characterized in that a substance with a refractive index higher than that of the volume hologram layer for shifting a recorded wavelength is contained in the first and/or the second adhesive layer(s) and in that a reproduced wavelength of hologram recorded in the volume hologram layer is shifted to a long wavelength side.
A volume hologram laminate according to a third invention is one having a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protecting film formed on a substrate in the described order, characterized in that a (meth) acrylic monomer is contained in the first and/or the second adhesive layer(s), in that the volume hologram layer is recorded holographically with light having a single wavelength (monochromatic hologram), and a half band-width value of a respective reproduced wavelength range is 30 nm or more.
Further, a volume hologram laminate according to the invention is one having a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protecting film formed on a substrate in the described order, characterized in that a (meth)acrylic monomer is contained in the first and/or the second adhesive layer(s), in that the volume hologram layer is color-recorded holographically with light having two or more wavelengths, and a half width value of a respective reproduced wavelength range is 20 nm or more.
The above-mentioned adhesive layer is preferably a crosslinking type two component adhesive which is crosslinked at the time of use by addition of a crosslinking agent.
The above-mentioned volume hologram layer comprises preferably a photopolymerizable compound, and the layer is recorded holographically.
A label for preparation of a volume hologram laminate according to the invention is one having a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protecting film formed on a release liner sheet in the described order, characterized in that a (meth)acrylic monomer is contained in the first and/or the second adhesive layer(s) and in that a half width value of respective reproduced wavelength range is 30 nm or more and in that a volume hologram layer is recorded holographically with light having a single wavelength.
Further, a label for preparation of a volume hologram laminate according to the invention is one having a first adhesive layer, a volume hologram layer, a second adhesive layer and a surface protecting film formed on a release liner sheet in the described order, characterized in that a (meth) acrylic monomer is contained in the first and/or the second adhesive layer(s), in that a volume hologram layer is color-recorded holographically with light having two or more wavelengths, and in that a half width value of a respective reproduced wavelength range is 20 nm or more.